Retirement offers Peter a chance to finally do what he always wanted to do - mess about with his telescope without having to watch the clock. One evening he is trying out some long discarded bits and pieces of circuits when the impossible happens - something disappears and then reappears as he watches. He investigates further and realises that he has discovered a priceless secret - time travel. Together with his wife's help he does some tests, only to find life-threatening problems - including his wife's inadvertent disappearance. With very limited time available he sets out on a rescue mission.